Battery charger



FIG. 1 is a top plan view of a battery charger showing the new design;

FIG. 2 is a bottom plan view thereof;

FIG. 3 is a left side elevational view thereof;

FIG. 4 is a right side elevational thereof;

FIG. 5 is a front side elevational view thereof;

FIG. 6 is a rear side elevational view thereof; and,

FIG. 7 is a perspective view thereof. 

What is claimed is the ornamental design for a battery charger, as shown and described. 